[Dev] Add filter to check whether file cache should be served

[Arkshine]

Hello,

I have a situation where I must redirect requests from a specific origin with conditions to a custom page.

I did some code; however, the redirection is overwritten by WP-Rocket when the page is served from the cache.

That would be nice to have a filter, I would say, in serve_cache_file() and serve_gzip_cache_file() : https://github.com/wp-media/wp-rocket/blob/develop/inc/classes/Buffer/class-cache.php#L167 to ignore the cache.